Attaching clip for two-prong electric plug



"milf May 17, 1955 w. ORSINH 2,708,741

ATTACHING CLIP FOR TWO-PRONG ELECTRIC PLUG Filed Nov. 20, 1952 5--1 Fig@135.4

IN V EN TOR.

HroR/VEY United )States Patent O ATTACHING CLIP FOR TWO-PRONG ELECTRICPLUG William Orsini, Waterbury, Conn. Application November 20, 1952,Serial No. 321,550 1 Claim. (Cl. 339-276) This invention relates toelectric plugs commonly used for connecting a power source with anelectric appliance, and more particularly to a strain relieving clip forattaching a cable wire to a terminal of such a plug.

Many such devices have been proposed in the past, but involved complexand complicated constructions, requiring the use of an excessive amountof cord and metal.

One object of the present invention is to provide a device of `the abovenature, having novel means for relieving the strain of the connectionbetween'lthe appliance cord and the plug.

A further object is to provide a device of the above nature which willbe simple in construction, inexpensive to manufacture, easy to installand manipulate, compact,

ornamental in appearance, and very efficient and durable in use.

With these and other objects in view, there has been,

illustrated on the accompanying drawing, one form in which tlieinvention may conveniently be embodied in practice.'

In the drawing,

Fig. lrepresents a top plan view of a strain relief clip embodying theinvention showing the offset staggered prongs bent up into a verticalposition.

Fig. 2 is an end view of the same.

Fig. 3 is a side view of the same.`

Fig. 4 is a plan view of the clip similar to Fig. l, be fore the prongshave been bent up.

Fig. 5 is a plan view of a blank strip of metal from which the clips arebeing stamped in interfitting relation to produce the minimum of scrap.

Fig. 6 is an end View of a two-prong plug having two of the strainrelief clips assembled therein according to the first method ofassembly. v

Fig. 7 is a view, similar to Fig. 6, in which one of the conductors hasbeen loosely embraced by the ears of one strain relief clip, and theother conductor has been clamped by the ears of the other clip.

Fig. 8 is an end view of a strain relief clip, and a stranded conductorwire loosely embraced thereby.

Fig. 9 is an end View of the clip after the ears have been tightlyclamped upon the conductor wire.

Fig. l0 is a plan view of the portion of a two-conductor cable with twostrain relief clips soldered upon the bared stranded ends of theinsulated conductors, according to the second and preferred method ofattaching said clips.

Referring now to the drawing, in which like reference numerals denotecorresponding parts throughout the several views, the numeral 10indicates a hollow two-prong plug having a pair of prongs 10a, 10bprojecting therefrom, said prongs having perpendicular bases 10c locatedon the inside of the hollow cap, within the cavity 11 thereof.

The numeral 12 indicates a rear aperture in the cap 10 through which theinsulated conductors 13 and 14 of the cable 14a are passed.

The numerals 15 and 16 indicate the bared stranded wlre ends of thecable conductors 13, 14 which are shown in Fig. 6 prior to beingattached to the bases 10c of the prongs 10a and 10b.

As clearly shown in Fig. 5, the attachment strain relief clips 18 ofthis invention are adapted to be stamped out of a blankvstrip of metal17 in succession as in a punch press, in such a manner that thesuccessive stampings are intertted with one another to produce theminimum amount of scrap 27.

The clips 18 are provided with curved ends 19, which embrace inclinedopen slots 20. The other ends of said clips 18 are provided with olisetears 21, 22 and open recesses 23, 24 on opposite sides of said clips.

As clearly shown in Figs. 8 and 9, the ears 21 and 22 are adapted to befirst bent up and then forced down into clamping engagement with thebared stranded wire terminals 15 and 16 into the shape shown in Fig. 9.

If desired, the clips 18 may first be attached to the bases 10cof theprongs 10a and 10b, and then locked in position by inserting the headedscrews 26.

According to the preferred method of assembly, however, the vclips 18will be permanently attached to the stranded wire ends l5, 16, bybending the ears 21, 22 into engagement with said wire and then securingthem thereto by means of solder 25, as clearly Vshown in Fig. 10.

One advantage of the present invention is that the scrap pieces 27 whichare located only on one side of the strip 17, are quite small therebylowering the cost of manufacture of the strain relief clip considerably.

Operation In operation, each strain-relieving clip may be attached tothe prongs 10a and 10b of the plug 10 by fitting the slot 20 on saidclip around the shank Vof the headed binding screw 26, which may then betightened by means of a screw driver or other tool.

The stranded wires 15, 16 of the cable may then be inserted through therear aperture 12 and placed between the upstanding ears 21, 22 of theclips 18, which ears will then be bent downwardly around said wires sothat the cord cannot be pulled out.

It will also be understood that when the alternative method of attachingthe clips to the plug is employed, the yclips will be first attached andsoldered to the stranded wire ends 15 and 16 and then inserted throughthe aperture in the plug, after which the headed binding screws 26 willbe tightened to clamp the clips in position within the plug 10.

While there has been disclosed in this specification, one form in whichthe invention may be embodied, it is to be understood that this form isshown for the purpose of illustration only and that the invention isnotto be limited to the specific disclosures, but may be modified andembodied in various other forms without departing from its spirit. Inshort, the invention includes all modifications and embodiments comingwithin the scope of the following claim.

Having thus fully described the invention, what is claimed as new, andfor which it is desired to secure Letters Patent is:

ln a strain relief metallic clip for detachably connecting the end of abare conductor wire to the base terminal Patented MayA 17, 1955 of atwo-prong electric plug, a strip metal member curved ai: one end andprovided with an inclined inwardly-extending parallel edged slot on oneside to embrace the shank of one of the binding screws of said plug, theother end of said member being provided with a pair of oppositelyextending longitudinal ears oset from each other, said member having apointed prong spaced from the ear on said slotted end defining arectangular recess which is adapted to intert with the ear on the otherend of Said member so as tofpermi-'t' production of a plurality of: saidclips by stamping them successively from coiled strip with the minimumof scrap.

References Cited in the file of this patent UNITED STATES PATENTSWheeler Aug. 30, 1887 McIntire Feb. 25, 1890 Schneider June 28, 1910Heineman Aug. 6, 1918 Conradi et al. July 2, 1940 Parker July 7, 1942

